Question

traffic lights at three different road crossings changes after every 48 seconds,72 seconds and 108 respectictly if they change simultaneously at 7 AM at what time will they change simultaneously again​

Answer 1

The traffic lights at three different road crossings change after every 48 seconds, 72 seconds, and 108 seconds respectively. If they change simultaneously at 7 a.m. at what time will they change simultaneously again?

Answer: The three lights will change simultaneously again at 7 hours 7 minutes 12 seconds in the morning, i.e., at 07:07:12 a.m.

Explanation:

We know that in order to find the time when the three lights will change simultaneously again after 7 a.m., we need to find the LCM of 48, 72, and 108.

Finding the LCM using the prime factorization method, we get the prime factors of LCM as :

Factors = 2 × 2 × 3 × 3 × 3 × 2 × 2 × 1 = 432

Hence, after converting 432 seconds into minutes and seconds, we get:

432 seconds = 7 minutes and 12 seconds.

Thus, the three lights will change simultaneously again after 7 a.m. at 7:07:12 a.m.

Thus, the three lights will change simultaneously again at 7 a.m. + 7 minutes and 12 seconds in the morning, i.e., at 07:07:12 a.m.

Answer 2

Step-by-step explanation:

First LCM of 48,72and 108.

then the answer would be 432 seconds

convert it to minutes.

then it would be 7.2 minutes.

it wi again change simultaneously at 7hour 7minutes and 2 seconds.